Balance and text changes

  *Fixed boomer ranged attack to not poison through poison resistance
  *Buffed smokestacks. They were too fragile, too expensive, and didn't
  do much. Added extra range on the poison cloud, dropped the price, and
  added more hitpoints
  *Gave the boomers slightly more hitpoints so that they would be better
  meatshields after using up their vomit
  *Slight increase to Vile Stalker's gold cost
  *Phoenix tril now has a description
  *Buffed Covus, Necromancer Enthroned. Lowered base cost, and new path
  cost
  *Childern of the allspawn are now capital only
  *Reduced the number of boomers in PD and increased the number of
  clattering shambler. Boomers in PD are pretty useless because it's easy
  to get them to waste their vomit.